redirect.pizza makes full domain redirects, i.e. fully qualified domain names to another. It's important to know you must own or have access to the domain you are trying to redirect.
For example, we provide services for old-domain -> new-domain.com or example.com -> www.example.com.
For redirect.pizza to function, you must have access to your domain provider to make the nessesary DNS changes. These DNS changes must happen at your DNS provider, in which cases is most of the time also the domain registration provider. To learn more about these DNS changes, see What are these DNS changes?